kiltedcelt
100 W
I'm not even sure how to research this using the "search" function. There's apparently too many variables to find an answer to the question. Anyway this is the situation. My bike (Yuba Mundo), currently has:
Mac 16t front geared hub motor
Infineon 6fet 3077 controller - 25 amps max output
36v battery 18.1 Ah
Cycle Analyst with PAS setup and a throttle
So, by doing the math the motor is capable of putting out up to 900w, but I rarely see that. I typically only blip the throttle to get the bike up to pedaling speed a little quicker when starting from a dead stop. The rest of the time I'm pedaling. Currently the PAS is configured in the CA to three settings - 50% 75% and 100%. I am usually fine using the lowest PAS setting and I can easily pedal with some moderate exertion and have the bike stay at between 17-20 mph. It's pretty well, table-flat here where I live so about the only time I bump up to 75% assist is if the headwinds are high, as in 20+ mph.
I'm swapping the 36v 18 Ah battery out for a 50.2v 27.9Ah battery in order to increase my range. My current range is only about 25 miles or so which cuts down drastically on the usefulness of the bike for my needs, especially because the only charger that will work on the battery is a 2amp charger that takes HOURS to charge back to full capacity. So, new battery equals greater range, but if I do the math again, we're now talking about a 1255w potential power output. This means 50% assist coming from the CA will mean with the new battery that 50% assist will actually be an even higher amount of watts and if I'm correct, a corresponding drop in range.
Currently, the 50% setting for PAS as configured in the CA allows me to pedal along using about 250w, coupled with my pedaling to keep me around 18 mph most of the time. I am perfectly happy with this. I don't mind going over 20 mph on occasion when the road is open with no traffic or obstructions, or on a path with no pedestrians or other cyclists around. I have ZERO desire to go 30+ mph on a regular basis, but I'm fine with having the option if I want it. As I figure it, the new battery seems like it will yield a higher wattage output at the 50% PAS level, which seems again like that would potentially cut into the greater range I'm looking for.
My other concern was limiting power output somewhat since this is a front hub motor. I've read about issues with high wattage front motors splaying out fork dropouts. For the record, I am using TWO high-quality Grin Tech torque arms on either side of the front fork, which itself is cro-moly steel. The torque arms are of the type that connects via bolt to the threaded tabs on the fork leg that would normally accept a fender stay or rack mount. The secondary concern here is that I don't want to increase power output so much that the front geared hub motor - already a VERY torquey model - becomes a safety liability.
In talking with Joseph at EM3ev (where I bought my original kit and the current replacement battery), he said if I was concerned about too much power, I could use my programming cable to limit power output from the Infineon controller to something less than the 25 amps max it's currently set at. So, I'm wondering if either lowering the controller output can help dial back power and increase range, or is this something I should control within the CA by dialing down the PAS from a baseline setting of 50/75/100% to maybe something like 30/60/100% or something similar? For the record, currently that 75% PAS level seems to output around 350w nominal power.
Edit- I was doing some more thinking and "ciphering" and it seems like if I leave the controller alone I still maintain the ability to have a top speed over 20 mph - probably 25 or so, maybe higher if I really push it with my pedaling output. So, maybe the best option is tweaking the Cycle Analyst PAS settings so that 50% doesn't equal ~627w, although, technically 50% of the current setup is actually 450w, but I don't get 450w in the 50% setting - only 250w or a bit more. So maybe limiting the wattage of PAS through the CA is the way to go? For that matter, why does the 50% level of PAS in my current setup equate to 450w but it really only provides about 250w nominal, although I see it go as high as 275 or 280? Likewise, the 75% setting should be about 675w, but it typically is putting out about 350-380w.
Mac 16t front geared hub motor
Infineon 6fet 3077 controller - 25 amps max output
36v battery 18.1 Ah
Cycle Analyst with PAS setup and a throttle
So, by doing the math the motor is capable of putting out up to 900w, but I rarely see that. I typically only blip the throttle to get the bike up to pedaling speed a little quicker when starting from a dead stop. The rest of the time I'm pedaling. Currently the PAS is configured in the CA to three settings - 50% 75% and 100%. I am usually fine using the lowest PAS setting and I can easily pedal with some moderate exertion and have the bike stay at between 17-20 mph. It's pretty well, table-flat here where I live so about the only time I bump up to 75% assist is if the headwinds are high, as in 20+ mph.
I'm swapping the 36v 18 Ah battery out for a 50.2v 27.9Ah battery in order to increase my range. My current range is only about 25 miles or so which cuts down drastically on the usefulness of the bike for my needs, especially because the only charger that will work on the battery is a 2amp charger that takes HOURS to charge back to full capacity. So, new battery equals greater range, but if I do the math again, we're now talking about a 1255w potential power output. This means 50% assist coming from the CA will mean with the new battery that 50% assist will actually be an even higher amount of watts and if I'm correct, a corresponding drop in range.
Currently, the 50% setting for PAS as configured in the CA allows me to pedal along using about 250w, coupled with my pedaling to keep me around 18 mph most of the time. I am perfectly happy with this. I don't mind going over 20 mph on occasion when the road is open with no traffic or obstructions, or on a path with no pedestrians or other cyclists around. I have ZERO desire to go 30+ mph on a regular basis, but I'm fine with having the option if I want it. As I figure it, the new battery seems like it will yield a higher wattage output at the 50% PAS level, which seems again like that would potentially cut into the greater range I'm looking for.
My other concern was limiting power output somewhat since this is a front hub motor. I've read about issues with high wattage front motors splaying out fork dropouts. For the record, I am using TWO high-quality Grin Tech torque arms on either side of the front fork, which itself is cro-moly steel. The torque arms are of the type that connects via bolt to the threaded tabs on the fork leg that would normally accept a fender stay or rack mount. The secondary concern here is that I don't want to increase power output so much that the front geared hub motor - already a VERY torquey model - becomes a safety liability.
In talking with Joseph at EM3ev (where I bought my original kit and the current replacement battery), he said if I was concerned about too much power, I could use my programming cable to limit power output from the Infineon controller to something less than the 25 amps max it's currently set at. So, I'm wondering if either lowering the controller output can help dial back power and increase range, or is this something I should control within the CA by dialing down the PAS from a baseline setting of 50/75/100% to maybe something like 30/60/100% or something similar? For the record, currently that 75% PAS level seems to output around 350w nominal power.
Edit- I was doing some more thinking and "ciphering" and it seems like if I leave the controller alone I still maintain the ability to have a top speed over 20 mph - probably 25 or so, maybe higher if I really push it with my pedaling output. So, maybe the best option is tweaking the Cycle Analyst PAS settings so that 50% doesn't equal ~627w, although, technically 50% of the current setup is actually 450w, but I don't get 450w in the 50% setting - only 250w or a bit more. So maybe limiting the wattage of PAS through the CA is the way to go? For that matter, why does the 50% level of PAS in my current setup equate to 450w but it really only provides about 250w nominal, although I see it go as high as 275 or 280? Likewise, the 75% setting should be about 675w, but it typically is putting out about 350-380w.
